Overview
ISO 17497-1:2004 - "Acoustics - Sound‑scattering properties of surfaces - Part 1" specifies a laboratory method to measure the random‑incidence scattering coefficient of surfaces caused by surface roughness. Measurements are performed in a reverberation room (full scale or on a physical scale model). Results quantify how much a surface’s reflection deviates from ideal specular reflection and are intended for material comparison and room‑acoustic or noise‑control design calculations. The method does not characterize the directional uniformity (spatial distribution) of scattering.
Key topics and technical requirements
- Measured quantity: random‑incidence scattering coefficient (one minus the ratio of specularly reflected acoustic energy to total reflected energy in a diffuse field).
- Measurement principle: obtain impulse responses for multiple sample orientations on a turntable; use synchronized (phase‑locked) averaging so specular components add coherently while scattered components average out.
- Frequency range: measurements in one‑third‑octave bands covering 100 Hz to 5 000 Hz (full scale); scale models use frequencies scaled by the physical scale ratio.
- Test environment: reverberation room arranged per ISO 354; diffusing elements fixed; temperature and humidity controlled.
- Sample geometry: circular test sample preferred, minimum diameter = N × 3.0 m for physical scale ratio 1:N (square samples allowed with specified edge dimensions and flush mounting).
- Structural depth: method intended for surface roughness; structural depth should be small relative to sample diameter (h ≤ d/16).
- Turntable and base plate: circular rigid base required; base‑plate scattering must be checked and limited to specified values.
- Data processing: measurement of impulse responses, evaluation of decay curves and calculation of scattering coefficient; presentation and reporting per the standard’s clauses.
Applications and who uses it
ISO 17497-1 is used by:
- Acoustic consultants and room‑acoustics designers (concert halls, studios, auditoria)
- Manufacturers of diffusers, acoustic panels, and surface treatments
- Acoustic test laboratories and standards bodies
- Researchers modeling reverberant spaces and noise‑control engineers
Practical uses include material comparison, input data for acoustic simulation/prediction, design of scattering to improve sound diffusion or control reflections, and verification of manufacturing quality.
Related standards
- ISO 354 - Measurement of sound absorption in a reverberation room (test environment requirements)
- ISO 9613‑1 - Outdoor sound attenuation (reference for atmospheric absorption)
- ISO 17497 (Part 2 under preparation) - directional diffusion coefficient (complements Part 1)
Keywords: ISO 17497-1, sound scattering, scattering coefficient, reverberation room, room acoustics, surface roughness, random‑incidence measurement.